Background: Wound infection affects a considerable portion of patients after abdominal operations, increasing health care costs and postoperative morbidity and affecting quality of life. Antibacterial coating has been suggested as an effective measure to decrease postoperative wound infections after laparotomies. The INLINE metaanalysis has recently shown the superiority of a slowly absorbable continuous suture for abdominal closure; with PDS plus® such a suture has now been made available with triclosan antibacterial coating. Methods/Design: The PROUD trial is designed as a randomised, controlled, observer, surgeon and patient blinded multicenter superiority trial with two parallel groups and a primary endpoint of wound infection during 30 days after surgery. The intervention group will receive triclosan coated polydioxanone sutures, whereas the control group will receive the standard polydioxanone sutures; abdominal closure will otherwise be standardized in both groups. Statistical analysis is based on intention-to-treat population via binary logistic regression analysis, the total sample size of n = 750 is sufficient to ensure alpha = 5% and power = 80%, an interim analysis will be carried out after data of 375 patients are available. Discussion: The PROUD trial will yield robust data to determine the effectiveness of antibacterial coating in one of the standard sutures for abdominal closure and potentially lead to amendment of current guidelines. The exploration of clinically objective parameters as well as quality of life holds immediate relevance for clinical management and the pragmatic trial design ensures high external validity. Trial Registration: The trial protocol has been registered with the German Clinical Trials Register (DRKS00000390).